Mark Olsen, chief information security officer at Beth Israel Deaconess Medical Center in Boston, said the hospital had 664 pieces of medical equipment running on old versions of Windows.

This means the equipment is affected by weaknesses which later releases of Windows have since fixed.

Kevin Fu, a leading expert in medical technology, explained that the machines were not updated because of fears that doing so would mean they were in breach of regulations put in place by the US Food and Drug Administration (FDA).

The FDA approve the use of technology by testing safety rather than security – meaning any potential exposure to cyberthreats is not considered.

Imagine you have a medical monitor that’s running Windows and it gets infected by a computer virus and slows down”

There are also fears, the panel agreed, that medical devices could even end up being part of botnets – large networks of hijacked computers that are often used to send out spam email.

Medical devices could be struck down by slow performance related to being infected, Mr Fu told the BBC.

“Imagine you have a heart monitor that’s running Windows and it gets infected by a computer virus and slows down.

“This mere slowing down of the computer could cause the device to miss a sensor reading. It certainly raises an eyebrow. Who’s watching out for that?”

He said that there is no evidence as yet that the malware is reaching medical machines as a result of being targeted by criminals.

Instead, he said it was more likely to be “collateral damage” from conventional malware designed to infect normal PCs.

“What we’re finding is that software has brought tremendous benefit to medicine, but we’ve kind of forgotten that there’s these inconvenient risks of software,” he said.

In the UK, the NHS faces similar challenges.

“The need to implement security and privacy at the design of all systems, whether they’re embedded or not is of paramount importance, particularly to the health industry,” said Raj Samani, who worked in the health sector and is now chief technology officer for security specialists McAfee.